The armour pieces/sets you can buy and find will give you various bonuses in different areas. Some will give you health bonuses, some will give weapon or headshot bonus damage, etc. There's a set of armour which increases melee damage.

You could probably do with a mixture of health/shield and melee bonuses.

EDIT: Found 'em for you.

Ariake Technologies armor increases your melee damage- you'll get almost a full bar with all four pieces.

Kassa Fabrication armor will give you a shield boost, along with shield regeneration.

N7 armor gives you a health boost.

[Edited by Skyheart, 3/16/2012 5:21:32 AM]

"Remember the good old days when you could just slap Omni-Gel on everything?" - Shepard, ME2